This section provides background information related to the present disclosure which is not necessarily prior art.
Modern combustion engines, e.g. of a motor vehicle, often include a fuel injection system having a fuel pump that delivers fuel at a high pressure to a fuel rail in fluid communication with a plurality of fuel injectors. Each of the fuel injectors corresponds to a combustion chamber of the engine and is designed for injecting metered quantities of fuel into the respective chamber. The injectors may be designed as solenoid valves. Often, the fuel injectors perform a plurality of injection pulses per engine cycle including a main injection and at least one additional injection, depending on the design of the engine and the emission requirements.
For maintaining a required accuracy for the individual fuel injections, it is known to determine the timing and quantity of the fuel injections and to conduct corrections where required. For example, it is known to analyze the fuel rail pressure over time to determine significant fuel rail pressure changes, from which timing and quantity can be calculated. This is exemplarily described in US 2016/0215708 A1.
By using a suitable digital filter on an acquired rail pressure signal a fuel quantity may directly be calculated based on a difference of rail pressure levels before and after the respective injection event. However, possible static errors caused by fuel leakages on the rail, which may be caused by a pressure regulator and/or an injector, are neglected in such an approach.
Accordingly, it is desirable to provide a method for determining timing and quantity of fuel injections with a sufficient compensation of potential leakage effects in the fuel rail system. In addition, it is desirable to provide a system that is capable of conducting such a method in a combustion engine. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.